function validate_required(field,alerttxt)
{
with (field)
{
if (value==null||value=="")
{alert(alerttxt);return false}
else {return true}
}
}


function validate_email(field,alerttxt)
{
with (field)
{
apos=value.indexOf("@")
dotpos=value.lastIndexOf(".")
if (apos<1||dotpos-apos<2) 
  {alert(alerttxt);return false}
else {return true}
}
}


function validate_form(thisform)
{
with (thisform)
{
if (validate_required(name,"Please enter your name")==false)
{name.focus();return false}
if (validate_required(email,"Please enter your email address")==false)
{email.focus();return false}
if (validate_required(message,"Please enter your message")==false)
{message.focus();return false}

if (validate_email(email,"I think you've made a mistake with your email address")==false)
  {email.focus();return false}

}
}


function validate_clubform(thisform)
{
with (thisform)
{
if (validate_required(name,"Please enter your full name")==false)
{name.focus();return false}
if (validate_required(email,"Please enter your email address")==false)
{email.focus();return false}
if (validate_required(email_confirmation,"Please confirm your email address")==false)
{email_confirmation.focus();return false}
if (validate_required(address,"Please enter your street address")==false)
{address.focus();return false}
if (validate_required(city,"Please enter your city/town")==false)
{city.focus();return false}
if (validate_required(postcode,"Please enter your postcode")==false)
{postcode.focus();return false}

if (validate_email(email,"I think you've made a mistake with your email address")==false)
  {email.focus();return false}
if (validate_email(email_confirmation,"I think you've made a mistake with your email confirmation")==false)
  {email_confirmation.focus();return false}

if ( ( document.club_form.age_group[0].checked == false ) && ( document.club_form.age_group[1].checked == false ) )
        { alert ( "Please choose your age group" ); under_20_years.focus();return false;  }

}
}